Medium-chain glycerides affect gut morphology, immune- and goblet cells in post-weaning piglets: In vitro fatty acid screening with Escherichia coli and in vivo consolidation with LPS challenge.

The influence of medium-chain glycerides on performance and gastrointestinal well-being in weaning piglets was assessed. First, caproic (C6), caprylic (C8) and capric (C10) acid activity against Escherichia coli was screened in vitro. Pig flora of the whole small intestine was used as inoculum. Seven in vitro incubations were done in duplicate at pH = 3 and 5: C10 (15 mM), C8 (12 mM), C6 (15, 12, 10 mM), a non-incubated-negative control and incubated negative control. Culture suspensions were plated on E. coli-selective agar. Controls showed bacterial growth. C6 and C8 showed no growth at both pH-values, where C10 showed growth at pH = 5. Secondly, an in vivo study was done with 80 weaned piglets over 42 days, housed in pens of eight animals (five pens/treatment), fed a basal diet containing broken rice/soya bean meal/fish meal and supplemented with C6 and C8 in medium-chain glyceride form (MCT6/8, 0.175%) or antibiotic growth promoter (AGP, 0.020%) (Kasetsart University, Thailand) serving as control. Feed intake, daily gain and feed-to-gain ratio did not differ between MCT6/8 and AGP. Per replicate, two random selected piglets were challenged intravenously with E. coli-lipopolysaccharide (LPS) or saline solution (S) at Days 21 and 28. All challenged animals were sacrificed; blood and digestive tract samples (jejunum/ileum) were collected at Day 35. LPS challenge consistently reduced villus height and crypt depth for MCT6/8 and AGP. However, LPS-challenged piglets supplemented with MCT6/8 restored villus height, where AGP did not. MCT6/8 piglets had higher serum IgA, more jejunal IgA-positive plasma cells and goblet cells than AGP. At the ileal level, results were similar, though less pronounced. The present study offers new insight in the benefits of MCT6/8 over AGP in the post-weaning period. There is in vitro anti-microbial action of C6 and C8 on E. coli. In vivo, MCT6/8 also has protective effects in the small intestine that may result in growth promotion.

Digestibility and metabolizable energy values of processed cassava chips for growing and finishing pigs.

Determinations of digestibility of dry matter (DM), digestible energy (DE), and metabolizable energy (ME) in cassava chips with different levels of crude fiber (CF) were measured in growing pigs (20 kg) and finishing pigs (60 kg). The treatments were (1) cassava starch (0% CF), (2) peeled cassava chips (2.5% CF), (3) non-peeled washed cassava chips (3.9% CF), and (4) non-peeled and non-washed cassava chips (5.2% CF). In the growing pigs, peeled cassava chips, non-peeled washed cassava chips, and non-peeled and non-washed cassava chips had DM digestibility of 87.51%, 78.63%, and 73.89%, respectively. Their DE was 3.69, 3.49, and 3.32 Mcal/kg DM, respectively (DE of cassava starch is 3.90 Mcal/kg DM). ME was 3.54, 3.35, and 3.19 Mcal/kg DM, respectively (ME of cassava starch is 3.74 Mcal/kg DM). On the other hand, in the finishing pigs, the digestibility of DM was 89.13%, 80.63%, and 76.13%, respectively. Their DE was 3.72, 3.53, and 3.43 Mcal/kg DM, respectively (DE of cassava starch is 3.91 Mcal/kg DM). ME was 3.57, 3.38, and 3.29 Mcal/kg DM, respectively (ME of cassava starch is 3.75 Mcal/kg DM). These values increased with decreasing CF content, and the peeled cassava chips had the highest values (P < 0.01). These suggest that the digestibility values of DM, DE, and ME of cassava chips is inversely related to the CF content in cassava chips. It is recommended that cassava chips be peeled for better nutrition for growing and finishing pigs.